Audience question asking how JRuby (especially on GraalVM) differs from TruffleRuby. Charles: TruffleRuby is not really a 'JVM Ruby' — it runs only on GraalVM and depends on it heavily for performance. TruffleRuby targets blazing-fast small benchmarks and tries to support C extensions; JRuby targets the whole ecosystem — pulling in JVM libraries, easy deployment, large production apps. JRuby has far more deployments and is effectively the only alternative Ruby with huge-scale production use. TruffleRuby also tends to use much more memory and still has a significant startup-time problem.